Gastric function and its contribution to the postprandial metabolic response of the Burmese python Python molurus
Stephen M. Secor
Department of Physiology, University of California at Los Angeles,
School of Medicine, Los Angeles, CA 90095-1751, USA and Department of
Biological Sciences, The University of Alabama, Tuscaloosa, AL 35487-0344,
USA
View larger version (10K):
[in a new window]
|
Fig. 1. Percentage of ingested meal remaining in the stomach as a function of time
postfeeding (days) for Python molurus. All pythons had consumed meals
equaling approximately 25% of their body mass. Mass of stomach contents was
measured from 3–8 pythons per sampling period. In this and all following
figures, error bars represent ±1 S.E.M. and are omitted if the S.E.M.
is smaller than the width of the symbol for mean value.
|
|
View larger version (90K):
[in a new window]
|
Fig. 2. X-rays of the midsection of a Python molurus taken at (A) 1 day,
(B) 2 days, (C) 3 days, (D) 4 days and (E) 6 days following consumption of a
rat weighing 25% of the snake's body mass.
|
|
View larger version (24K):
[in a new window]
|
Fig. 3. Intragastric pH of Python molurus (N=7) as a function of
time postfeeding (days). The insert illustrates the position of the pH
electrode (attached to the rat's head) within the python's stomach. Note the
decline in gastric pH following feeding and subsequent return after 7–9
days of digestion. The dotted portion of the x-axis signifies that
the initial increase in pH upon completion of gastric digestion began
6–8 days postfeeding.
|
|
View larger version (10K):
[in a new window]
|
Fig. 4. The time (days) it took after feeding for stomach pH of Python
molurus (N=6) to return to prefeeding levels plotted as a
function of meal size (% of snake body mass). Note that as relative meal size
increases so does the duration of maintaining an acidic stomach.
|
|
View larger version (11K):
[in a new window]
|
Fig. 5. Mean  O2 at
30°C of Python molurus prior to (day 0) and up to 10 days
following the ingestion of (A) intact rats, (B) steak, (C), ground rat, (D)
liquid diet and (E) ground rat directly infused into the proximal small
intestine. All meals were equal in mass to approximately 25% of snake body
mass. Note the decrease in the magnitude of the postfeeding metabolic response
as the workload on the stomach is reduced from digesting intact rat to
intestinally infused ground rat meals.
|
|
View larger version (26K):
[in a new window]
|
Fig. 6. Total specific dynamic action (SDA; 600 kJ) of a 1 kg Python
molurus resulting from the digestion of a rat meal equal in mass to 25%
of the snake's body mass, partitioned among the components of gastric
performance, protein synthesis, gastrointestinal (GI) upregulation and other
activities. Note in this example that the energy expended on gastric
performance is the largest component of SDA.
|
|
© The Company of Biologists Ltd 2003
